TABLE CONTENTS

Cold Tolerance Mechanisms of Entomopathogenic Nematodes
Farman, A. & D.A. Wharton
Department of Zoology, University of Otago, PO Box 56, Dunedin, NZ
Insect parasitic nematodes of the genera Steinernema and Heterorhabditis have considerable
potential as biological control agents, since they can be cultured in vitro in large quantities. A
major barrier to their large-scale commercial application, however, is the lack of a suitable
technique for their long-term storage. Attempts to base a storage technology on desiccation
and anhydrobiosis have met with limited success. However, some promising results have
been obtained using freezing. We summarise this work and describe how our understanding
of the cold tolerance mechanisms of Antarctic nematodes may assist in the development of a
storage technology for entomopathogenic nematodes based on freezing.
An Entomoparasitic Adult Form of Bursaphelenchus luxuriosae
Kanzaki, N. (1), (2), N. Maehara (3), T. Aikawa (2), R.M. Giblin-Davis (1) & B.J. Center (1)
(1) Fort Lauderdale Research & Education Center, University of Florida/IFAS, 3205 College Avenue, Davie,
FL 33314 USA; (2) Forest Pathology Laboratory, Forestry and Forest Products Research Institute, 1
Matsunosato, Tsukuba 305-8687 Japan; (3) Tohoku Research Center, Forestry and Forest Products Research
Institute, 92-25 Nabeyashiki, Shimo-Kuriyagawa, Morioka, Iwate 020-0123 Japan.
An entomoparasitic adult form of Bursaphelenchus luxuriosae was found in the tracheal
system and body cavity of its carrier host, Acalolepta luxuriosa (Cerambycidae). Because of
its characteristic morphology, the nematode was not originally identified as a
Bursaphelenchus species, but was considered to be an aphelenchoid insect parasite. However,
the molecular sequence (SSU barcode) of the parasitic form was identical to a cultured
population of B. luxuriosae and was subsequently confirmed as conspecific.
Morphologically, the parasitic form shares several characters with the phoretic dauer juvenile
stage of Bursaphelenchus nematodes and the parasitic juvenile stage of Parasitaphelenchus
species. The parasitic form has a dome-shaped head without a clearly separated lip region and
degenerate digestive organs, i.e., stylet, metacorpus and pharyngo-intestinal valve. The
parasitic form also has several similarities to mycophagous adults; a typical set of seven
caudal papillae and clearly defined cucullus on the spicules of males and a long vulval flap,
postuterine sac, and similar arrangement of the reproductive system of females. Besides these
characters, the parasitic form exhibits several apomorphic attributes, eg., four vacuole-like
dots (assumed to be a sensory organ) at its lip region, elongated and thin spicule (lamina /
calomus complex) of males and conical tail of females. Molecular phylogeny was used to
infer that Bursaphelenchus luxuriosae is basal to the ‘xylophilus’ group and adult insect
parasitism is presumed to be an autapomorphy. This is the first confirmed report of an
entomoparasitic adult form in the genus Bursaphelenchus.
5 th International Congress of Nematology, 2008 221